OPG/RANKL/RANK系统参与牙槽骨吸收及重建过程作用初探

Role of OPG/RANKL/RANK system during alveolar bone resorption and remodeling

目的初步探讨护骨素OPG、核因子κB受体活化因子配体RANKL、核因子κB活化因子RANK在牙周炎牙槽骨吸收及骨重建过程中的作用。方法对小鼠单核巨噬细胞白血病细胞株RAW264.7实验组进行体外诱导培养,对照组为完全培养基培养;小鼠成骨样细胞株MC3T3-E1实验组采用前期实验收集的骨吸收上清处理,对照组采用完全培养基培养;以免疫荧光等方法检测细胞OPG、RANKL、RANK的表达。30只8周龄雄性SD大鼠建立实验性牙槽骨吸收模型,研究其吸收重建规律。以免疫组化S-P法检测OPG、RANKL、RANK的表达情况。结果实验组MC3T3-E细胞经骨吸收上清处理7 d后,OPG蛋白平均荧光强度为(29.636±5.652),对照组为(15.568±1.229),表达显著上调(P<0.01);但实验组RANKL蛋白平均荧光强度为(6.806±1.738),对照组为(18.082±2.732),表达被显著抑制(P<0.01),OPG/RANKL比值在上清处理后高于对照组(P<0.05)。采用大肠杆菌内毒素E-LPS注射法成功制备大鼠牙槽骨吸收模型。在牙槽骨吸收区域OPG水平较无骨吸收区域有所降低,RANKL的表达则相反。结论 OPG、RANKL、RANK参与了大鼠实验性骨吸收活动;破骨细胞骨吸收上清可能通过改变OPG与RANKL的比值,从而影响骨重建中骨形成与骨吸收的动态平衡。

Objective To investigate the potential role of a system containing osteoprotegerin （OPG）, receptor activator of NF-KB ligand （ RANKL）, and receptor activator of nuclear factor-kappa B （ RANK）, also as, OPG/RANKL/RANK system in the resorption and remodeling mechanisms of alveolar bone. Methods Mouse RAW264.7 cell line was induced to osteoclasts in vitro, and mouse MC3T3-E1 cell line was treated with bone resorption supernatant. The control cells was cultured with regular medium. The expression levels of OPG, RANKL and RANK in the cells was detected by immunofluorescenee assay. Thirty 8-week-old male SD rats were used to establish the alveolar bone resorption model with the injection of E-LPS. Immunohistochemical S-P method was used to investigate the expression of OPG, RANKL and RANK in the animal model. Results The expression of OPG in MC3T3-E1 cells was up-regulated after 7 days＇ treatment with bone resorption supernatant than in control cells （29. 636 ± 5. 652 vs 15. 568 ± 1. 229, P 〈 0. 01 ）, while, the RANKL expression was down-regulated （6. 806± 1. 738 vs 18. 082 ±2. 732, P 〈0. 01 ）. The ratio of OPG to RANKL was up-regulated too （P 〈 0.05 ）. The OPG level in periodontal tissues of rats was decreased compared with the tissue without resorption. But the expression of RANKL was increased. Conclusion OPG/RANKL/RANK system is involved in the bone resorption and remodeling. Osteoclast bone absorbent supernatants might affect the ratio of OPG to RANKL by regulating of the differentiation and activity of osteoblast-like cells, and thus regulate the dynamic balance of bone formation and resorption.